Refining lubricating oil



Patented Apr. 16, 1935 Prat ori ice EEFINING LUBRICATING OIL Eugene Jerome Smith, Ponca toContinental Oil Company,

City, Okla, assignor Ponca City, Okla,

. a corporation of Delaware N Drawing.

. Application October 8, 1932,

Serial No. 636,945

6 Claims. (Cl. 196-423) Petroleum and most petroleumproducts have colors ranging from brown, reddish brown or black brown to black when examined by transmitted light. This property of a petroleum product-is only of minorimportance, even though some of the products of distillation or the crude oil residue are to be used for lubricating oil manufacture. However, the appearance oi'the samples by reflected light is of particular importance if the manufacture of lubricating oils is contemplated.

Lubricating oil sales are greatly influenced by the appearance of the lubricant by reflected light. This is variously referred to as the cast, tone or bloom of the lubricant. ,lvlost crude oils and all crude oils used for lubricating oil manufacture have a'more or less strong cast or bloom which is increased as the light (gasoline and kerosene) non-fluorescent hydrocarbon fractions are removed. The cast of various crudes vary in color. With some crude oils the bloom is blue or brownish blue and the like, While in others the cast can be described asa bright, clear green tone sometimes referred to asabright olive green. The particularly desirable green bloom or tone is easily discerned by those skilled in the art of lubricating oil manufacture even though it is difiicult to describe.

Bloom of some lubricating oils is not materially altered or changed by ordinary sulphuric acid and alkali treatment, While in others a change will occur. Bydrasticacid and/or alkali treatment the fluorescence of practically all lubricents is altered. Moreover, vacuum distillation of lubricating oil stocks almost always reduces the fluorescence or bloom of lubricating stocks or alters the particular tone. With the old art it has been very difficult to retain a desirable v bloom in lubricants during the necessary physical and chemical treatment required for its refinement, and if the original crude oil was lacking in this very desirable characteristic, the crude could not be used for lubricating oil manufacture, or if used, the lubricants obtained must be marketed as an inferior-product at a reduced price.

An object of my'invention is to provide a process by which the fluorescence or bloom of a lubricant can be maintained during treatment or modified if not of the desired shade.

Another object of my invention is to provide a means of supplying the desired fluorescence or bloom to lubricants originally lacking in this desired characteristic.

, lecting the stage or point in the shall be combined with the other known lubricat.

Another object of my invention is to provide lubricants with any desired green fluorescence or bloom by a method easily controlled and independent of the particular fluorescence or bloom of the crude oil from which the lubricant was, 5 made.

A further object of my invention is to obtain a quicker and more nearly complete acid sludge settling and/or acid pepper sludge settling by the addition of a small amount of an aldehyde during the process of refining lubricants and prior to the last acid wash or treat. Settling of pepper sludge: decreases the amount of clay necessary to neutralize the oil and obtain the desired color of the finished lubricant.

My invention accomplishes the objects of my invention very economically and without in any way effecting the other chemical and physical properties of the finished lubricants. v

In outline my process consists of adding an aldehyde totthe lubricating oil stock during the process of treatment but prior to a final acid treatment. Only small amounts of an aldehyde are required to accomplish the desired result. A number of factors should be considered in se-- refining process for the addition of the aldehyde. Some of these factors are:

1. The oil being treated.

-2. Strength of acid being used;

3. The particular aldehyde being used.

4. The amount of aldehyde which is to be used.

5. The number of dumps or stages ofthe acid treat. I

As previously stated the additionof an aldehyde must be followed by a sulphuric acid treatmentor wash to accomplish the desired result and remove the aldehyde odor.

It is intended that the herein described method ing oil refining processes as an improvement in the known processes. v

v In some oil refining processes brown fluorescent bodies are added tothe lubricatingoil. My in-.. vention of adding an aldehyde to an oil so blended gives a great improvement in the finished product.. The aldehyde may be added to the oil prior to the addition of the brown fluorescent bodies with the brown fluorescent bodies, or after the addition of the brown fluorescent substances, and in each case the desired result obtained.

Examples will serve to clarify the invention but should not be understood-as a limitation to the invention.

Example 1 0.03% of commercial furfural was added to a raw lubricating stool; and thoroughly blended by air blowing at ordinary temperatures and the oil treated by the usual aoid-clay process. The finished oil had the desired bloom or cast. Another sample of the same stock treated in the same manner with the exception of the additionof the aldehyde gave a final product of unsatisfactory bloom or fluorescence.

Example 2 Example 3 Lubricants obtained from a vacuum distilled lubricating stock were not satisfactory in fiuorescence or bloom characteristics when treated by the ordinary refining processes. Adding 0.3% furfural just prior to a final acid treat with the same stock and same treating process gave a finished lubricant with the required bloom.

In all of the above examples the pepper sludge settling was much quicker and more nearly complete with the aldehyde added.

In treating oils the pepper sludge settling is often a very serious problem and at best is usually a time consuming expensive step, due to the large amount of clay required to get the specified color and neutralize the oil. I have found that the addition of an aldehyde'as above described gives a much shorter acid sludge settling time. Aldehydes added to the acid oil after the heavy sludge has been drawn will tend to collect the pepper sludge and give clear pepper free oil in a short period of time.

The addition of an aromatic alcohol such as phenol prior to adding the aldehyde has a very desirable effect. the phenol has a tendency to break emulsions but in most cases it does not noticeably change the bloom or fluorescence of the finished lubricant; therefore to obtain fluorescence an aldehyde should be used in conjunction with the aromatic alcohol as a rule.

Much smaller quantities of aldehyde will give the pepper sludge separation than are generally required to produce the fluorescence or bloom characteristic.

Example 4 5 cc. per gallon of commercial phenol blended with the raw lubricating stock prior to the addition of an aldehyde and ti e final acid treat will greatly improve the final bloom of the finished lubricant, and give a quick and efficient emulsion break and pepper sludge separation. Quantities Among other desirable actions as low as cc. of phenol per gallon have been found entirely satisfactory in giving the desired result.

This process may be conducted at atmospheric temperatures as recited in Example 1; however, elevated temperatures give the desired result and in some cases should be used. Temperatures of 300 F. have been employed-in scmecases with the desired result obtained. With one oil 160 F. gave the best treating temperature. The aldehyde may be added and the process conducted at temperatures ranging from atmospheric or below, to 300 F. or above, the actual temperature used depending upon the oil being treated, the treating process, aldehyde used, and the desired result.

The word aldehyde used throughout this specification is intended to include the aromatic and/or aliphatic aldehydes and products which would be transformed into aldehydes under conditions of the acid treat or refining process. The amount of aldehyde to be'added may be varied from. 0.01% to 3.0% by volume depending upon a number of variable factors.

Having thus described my invention, what I claim is:

oils a process including the step of adding from one hundredth of one percent to three percent of furfural to the oil being refined before the final acid treatment thereof whereby to impart a de-,

sired bloom to the refined oil.

2. In therefining of hydrocarbon lubricating oils a process including the step of adding a small amount of furfural to the oil being refined before the final acid treatment thereof whereby to im than three percent of furfural to the oil being refined before the final acid treatment thereof whereby to impart a desired bloom to the refined oil.

4. A process for refining hydrocarbon lubricating oils including the steps of adding from .01

percent to '3 percent of furfural to the oil being processed and subsequently treating the oil with acid, whereby to decrease the settling time for the acid sludge and to obtain the desired cast.

5. A process for refining hydrocarbon lubricating oils including the steps of adding from .01 percent to 3 percent of furfural and an aromatic alcohol to the oil being processed and subsequently treating the oil with acid, whereby to decrease the settling time for the acid sludge and to obtain the desired cast.

6. A process for obtaining the desired cast in hydrocarbon lubricating oils and decreasing the acid sludge settling time including the steps of adding at least one hundredth of one percent of furfural and at least a half a cubic centimeter of an aromatic alcohol per gallon of oil to the oil being treated, and treating the mixture with acid.

EUGENE JEROME SMITH.

. 1. In the refining of hydrocarbon lubricating 

